/Engine/Source/Runtime/GeometryCore/Public/DynamicMeshEditor.h
Assumes that Submesh has been modified, but boundary loop has been preserved, and that old submesh has already been removed from this mesh. Just appends new vertices and rewrites triangles.
true if submesh successfully inserted, false if any triangles failed (which happens if triangle would result in non-manifold mesh)
bool ReinsertSubmesh ( const [FDynamicSubmesh3](API\Runtime\GeometryCore\FDynamicSubmesh3) & Submesh, [FOptionallySparseIndexMap](API\Runtime\GeometryCore\Util\FOptionallySparseIndexMap) & SubToNewV, [TArray](API\Runtime\Core\Containers\TArray)< int > * NewTris, [EDuplicateTriBehavior](API\Runtime\GeometryCore\FDynamicMeshEditor\EDuplicateTriBehavior) DuplicateBehavior )